How Delaware's Primary Election Works

Delaware uses a closed primary system. Registered Democrats may vote only in Democratic primaries, while registered Republicans may vote only in Republican primaries. Unaffiliated voters and voters registered with another party generally cannot participate in either major party's primary unless they change their party affiliation by the applicable deadline.

For the 2026 primary, certain voters who were automatically registered through Delaware's Automatic Voter Registration system and remain listed as "No Party - AVR" have a special exception allowing them to affiliate with the Democratic or Republican Party through Primary Election Day and then participate in that party's primary.

Delaware does not hold primary runoff elections. Candidates only need to receive a plurality of the vote to win their party's nomination, meaning the candidate with the most votes becomes the party's nominee even if they do not receive an outright majority.